Sensory Processing

The Oxford dictionary (1990, p.399) defines the word process as a series of operations used in making or manufacturing something, a procedure. In SI, sensory processing is defined as the ability and process of interpreting the information the brain has received via the senses (Daniels & Dunn, 2000).

Sensory processing is similar to the reference of perception within psychology literature, which will be discussed below.

Psychology literature indicates two phases that follow one another in allowing an individual to gain the required information about the world around him/her (Louw

& Edwards, 1997). The two phases are sensation and perception (Louw &

Edwards, 1997). Sensation in its simplest definition is the stimulation received via the senses (Louw & Edwards, 1997). The senses have been discussed in the previous section. Sensation is therefore the process through which the senses allow information to enter the individual (Louw & Edwards, 1997). In SI literature, sensation is similar to sensory acuity. Sensory acuity is the actual physical ability of the sensory organs of the individual’s body to receive the incoming input (SPD Network, Introduction to concepts, 2006).

Perception follows the process of sensation gathering and the perception processes allow for the assignment of meaning to the sensory stimulation received from the environment (Louw & Edwards, 1997). The process of perception involves the selection, organisation and interpretation of the sensory stimuli (Louw &

Edwards, 1997). Once again echoing previous discussions, sensory integration is what turns sensation into perception (Emmons & Anderson, 2005). As perception defines the reality for an individual, sensory integration defines the reality as what is that unique perspective of the world around that particular individual (Emmons

& Anderson, 2005).

In conclusion, there is a difference between sensory processing and sensory acuity, although both functions are required within an individual for the brain to interpret information entering the body (SPD Network, Introduction to concepts, 2006). The term “sensory acuity” in the field of SI is similar to the term

“sensation” in psychology literature. Furthermore, the term “sensory processing”

in SI literature is similar to the term “perception” in the field of psychology.

These similarities among the professional disciplines once again serve to prove the legitimacy of recognition of the concepts.

One central aim of all health professionals is to gain a better understanding of human beings in an attempt to better assist their patients/clients. Dunn (2001) states that one unique contribution that occupational therapy knowledge brings to the fore is within the understanding and meaning attached to the sensory

experiences of individuals. This understanding of sensory processing followed by noting the impact on the individual’s function within his/her life aids us in further understanding being human. In defining the role of occupational therapists within the health team, Dunn states:

“We make the applications to daily life to which other disciplines only allude.

We might characterize our role as translator: We stand in the space between abstract constructs and application to practice, looking back and forth translating for each group what the other has to say. Therefore, we can inform colleagues about the meaning of their research and families about their situations, enabling each group to advance their own thinking and ultimately advance knowledge overall.” (Dunn, 2001, p.609).

This was similarly stated by Emmons and Anderson (2005) who declared that they felt, as parents of children with SI challenges, that if they figured out more about the sensory challenges that they would be able to interact more positively and effectively with them, that they would then be able to improve the quality of their lives.

In the present study with university students at UWC, the researcher similarly endeavours to use occupational therapy knowledge to provide insight on the

learning encounters and challenges experienced by first year students, with similar ambitions in mind as expressed above.

2.2.8.4. Model of Sensory Processing

Dunn is a key theorist in the development of knowledge and understanding of sensory processing (Dunn, 1997). She developed the Model of Sensory

Processing and the Sensory Profile assessment tools for different age groups. The Infant-Toddler Sensory Profile was developed alongside Debora Daniels in 1994 and published after numerous research studies related to validation of the

assessment tool were conducted (Daniels & Dunn, 2000; Dunn, 1994; Dunn, 1997; Dunn & Brown, 1997; Ermer & Dunn, 1998). The principal component factor analysis research that was done on the Sensory Profile used in children assisted in the conceptualization of Dunn’s Model of Sensory Processing (Dunn, 1997). More information about the studies that incorporated the Sensory Profile assessment tools will be discussed later in this chapter under the topic of the Sensory Profile.

The Model of Sensory Processing demonstrates a relationship between the individual’s neurological threshold within the body and the behavioural response produced (Brown, Tollefson, Dunn, Cromwell & Filion, 2001). A threshold can be defined as the point at which stimulation is strong enough to be noticed (Kosslyn & Rosenberg, 2006). A low threshold therefore refers to a great

sensitivity for distinguishing a stimulus (Kosslyn & Rosenberg, 2006). According to the Model of Sensory Processing, on a neurological level the quadrants

represent high and low poles (Brown, 2001). The high and low poles relate to the intensity of the thresholds.

The basic patterns of responding to sensory events in everyday life can be noted in the four quadrants in Dunn’s model depicted in Table 1 below (SPD Network-Introduction to sensory processing concepts, 2006). The four quadrants are low registration, sensation seeking, sensory sensitivity and sensation avoiding (Brown, 2001).

TABLE 1.

Dunn’s Model of Sensory Processing (Brown & Dunn, 2002, p.8) Neurological Threshold

Continuum

Self Regulation Behavioural Response Continuum

Passive Strategies (Accordance) ↔ Active Strategies (Counteract)

Low Registration

Slow to respond, misses cues, easily adaptable to a variety of

settings.

Readily notices or aware of sensory features of the environment, distractible.

Sensation Avoiding

When bothered by stimuli engages in behaviours to limit sensory stimuli, does well with consistency,

routine.

The first quadrant within Dunn’s model is entitled “low registration” which suggests that the individual has a high neurological threshold to incoming stimuli (Dunn, 1997; Brown, 2001; Brown et al., 2001). In other words, a high degree of stimuli is needed for a behavioural reaction to be noted within the individual (Dunn, 1997; Brown, 2001; Brown et al., 2001).

The second quadrant within Dunn’s model is entitled “sensation seeking” and this is the behavioural strategy that counteracts the high neurological threshold of quadrant one (Brown, 2001; Brown et al., 2001). The behavioural responses are self-regulating strategies that can either be in accordance with the neurological threshold or counteractive of it (SPD Network-Introduction to sensory processing concepts, 2006). A counteractive behavioural manner indicates that the individual does not respond in line with his neurological threshold. The Oxford dictionary (1990, p.109) defines the word counteract as to reduce or prevent the effects of something and this is precisely what is meant by a counteractive behaviour.

In a scenario where the individuals are low registrators, they tend to immerse themselves in situations with lots of sensory stimuli to engage their nervous systems, as the term “sensory seeking” implies. An example of a low registrator is in the viewpoint of the olfactory sense, this person would be in the buffet line surrounded by the food, but doesn’t notice the smells of the food or may only notice the most pungent odours (Brown, 2001).

The lower quadrants within Dunn’s model relate to low neurological thresholds.

Quadrant three is entitled “sensory sensitivity” and suggests that this individual’s behavioural response is in accordance with a low threshold. A low threshold tendency means that this individual becomes easily aware of sensory stimuli for a behavioural reaction to be noted (Dunn, 1997; Brown et al., 2001). A sensory sensitive individual, in the same viewpoint of the olfactory sense and being in a food buffet line mentioned in the example above, would quickly register and be able to distinguish between the different odours of food (Brown, 2001).

The fourth quadrant is entitled “sensation avoiding”. This refers to the

behavioural strategy that counteracts the low neurological threshold (Brown et al., 2001). In this scenario the individuals who are sensory sensitive counteract by avoiding sensory situations, as the term “sensation avoiding” implies.

It is important to note that individuals can have responses at any point of the low and high neurological threshold continua (Brown, 2001). This is in relation to the different senses of the individual.

“Dunn’s Model of Sensory Processing depicts sensory processing preferences as stable traits; therefore, applying the model to adults is inherently

reasonable.” (Brown et al., 2001, p.76)

The above quote supports the use of this model with adults and thereby links with the rationale for applying it to the university students within this present study.

2.2.8.4. (i). Behavioural characteristics

According to Brown (2001), each of the sensory processing preferences of the four quadrants has both assets and liabilities. Whether or not a preference is an asset or a liability is dependent upon the task, situation and environment (Brown, 2001).

Certain behavioural characteristics have been depicted according to each of the four sensory processing quadrants. The high neurological threshold individuals (low registrators) have typically been characterized by a slowness to respond or a missing of information (Brown, 2001). Individuals with low registration may be less aware of things happening within their environment than others (Brown, 2001). To emphasize once again, an individuals’ sensory preference could be viewed as either an asset or liability, depending on the viewpoint one uses. One would assume that being less aware of input from the environment is a liability, but in the same instance, the asset of it is that individuals of the low registration type are generally good at tolerating a variety of different environments and they are able to maintain focus on tasks that they are interested in, despite distractions being present within the environment (Brown, 2001).

The second quadrant of the high threshold type (low registration type) is the sensation seeking type (Brown, 2001). The sensation seeking quadrant depicts behavioural characteristics that counteract the high neurological threshold (Brown, 2001). Individuals who are sensation seekers create or pursue

environments that offer a variety of sensory input that are intense enough to cause the neurological system to respond to sensation (Brown, 2001). These individuals therefore tend to enjoy sensory experiences and have generally been noted to be curious (Brown, 2001). They are easily bored and have difficulty with situations where routines and structure are required (Brown, 2001). They therefore present with restlessness in sedate, quiet environments (Brown, 2001).

The low neurological threshold individuals (sensory sensitivity) have typically depicted behaviours of “sharp awareness of sensory features in the environment,

distractibility, and a tendency to be bothered or overwhelmed by sensory

stimulation” (Brown, 2001, p.119). Individuals with high sensory sensitivity are

“inclined towards strong attention to detail and an ability to detect stimuli that others don’t notice” (Brown, 2001, p.119). It can be imagined that these

behavioural characteristics could be ideal in relation to professions or employment situations where this is required.

The fourth and final quadrant of the low threshold type is the sensation avoiding type (Brown, 2001). The sensation avoiding quadrant depicts behavioural characteristics that counteract the low neurological threshold (Brown, 2001).

Individuals who are sensation avoiding display deliberate behaviours to block exposure to stimuli, in line with the type of stimuli they find overwhelming, namely stimuli that perhaps affect the individuals’ auditory or tactile system (Brown, 2001). These individuals desire control over situations to aid in their coping (Brown, 2001). They prefer consistency and ritual, and have good skills in creating structure or routine (Brown, 2001).

In order to practically consider the different behaviours described above, the following is an example of four students in a university setting, where each

student features one of the four sensory processing types. The first student is seen taking lots of notes, not really trying to make sense of the information the lecturer is providing, but rather preferring to make sense of the information later. This could be an individual who is a low registrator, the first quadrant. The second student is chewing bubblegum, looking around and is wiggling in his chair. This could be an individual who is a sensation seeker, the second quadrant. The third student is observing the detailed overheads that the lecturer is making use of.

This could be an individual who is sensory sensitive, the third quadrant. The last student is sitting in the front row of the class and enjoys the fact that the lecturer is keeping to the format structured. This could be an individual who is sensory avoiding, the fourth quadrant.

All of the above indicate where sensory tendencies relate to habits observed within individuals. Dunn, the developer of the Model of Sensory Processing described above as well as the Sensory Profile instruments that will follow below, indicated in research how the habits could be supportive of daily routines, and cumbersome whereby the habits interfere with daily routines within the individual’s life (Dunn, 2000). This literature supports the idea of gaining an understanding of the sensory tendencies of university students as a means of advising, assisting and catering for their needs to afford them and the tertiary institution, academic success.

2.2.8.5. Sensory Profile for adolescents and adults

The Adolescent and Adult Sensory Profile (AASP) was developed in 1997 and published after validity research had been conducted (Brown, Tollefson, Dunn, Cromwell & Filion, 2001). The AASP is in the form of a self-questionnaire booklet with 60 questions related to individuals’ daily experiences related to the five senses as well as the three ‘hidden’ senses, described previously. This standardized assessment provides a measure of the effects of sensory processing on the functional performance of individuals within their daily lives (SPD Network, Technical Report, 2006).

The AASP is based on the Sensory Profile (Dunn, 1999), the measure developed for use in young children between the ages of three and ten years (Brown & Dunn, 2002). Although many of the items from the Sensory Profile for children

questionnaire were utilised for the inception of the AASP, modification of items occurred to allow the AASP to serve as a self-report and to deem the questions appropriate to an adolescent and adult age group (Brown & Dunn, 2002).

The AASP has been used in the present study to yield information about the first year students’ SI profiles. It is important to note that in all occupational therapy research studies to date, reference to the obtained information from the Sensory Profile for children and the AASP has been termed the ‘sensory profile’ of the participants. The researcher however decided on the term ‘sensory integrative profile’ due to the fact that the present study spans the two fields of Health and

Education, and this term was better understood and conveyed what had been investigated.

Brown and Dunn (2002) warn that there are certain considerations to keep in mind when interpreting the AASP, which would then provide the SI profile scores.

Brown and Dunn (2002) assert that all sensory processing tendencies have advantages and disadvantages, and therefore, there can be no tendencies that can be viewed as inherently good or bad. The task at hand and the context of the environment could determine whether the particular sensory processing tendency would be advantageous or disadvantageous (Brown & Dunn, 2002). An example of this is that an individual who has high scores in the Sensory Sensitivity

quadrant could then do well on tasks requiring precise sensory detections like a wine tester, however the disadvantage of this sensory processing tendency would be that the individual would be distracted in distracting environments such as a factory (Brown & Dunn, 2002).

Other considerations when interpreting the AASP are to view the entire pattern of scores across all the quadrants (Brown & Dunn, 2002). This is furthermore amplified by the fact that any combination of scores can occur (Brown & Dunn, 2002). Each of the four quadrants is independent and therefore any combination of scores is possible (Brown & Dunn, 2002). All scores are therefore telling and interesting, therefore the acquired low scores may be just as meaningful as high scores (Brown & Dunn, 2002). Within clinical situations whereby a health professional would administer the AASP to a client and thereafter utilise the obtained SI profile information for intervention purposes, the health professional would need to intensely observe the entire pattern across all of the four quadrants noting the scores pertinent to the clinical aspects requiring intervention.

Within the present study that deals with SI profile scores as well as academic marks or scores, the researcher utilised the obtained scores from all of the four quadrants, and conducted statistical analyses by correlating the scores of individual quadrants with the academic marks. More information about the

analysis of the obtained data of the present study will be presented in Chapter Three. The reliability and validity tests conducted during the development of the AASP will be discussed in more detail in Chapter Three. Research studies whereby the AASP or sensory profile characteristics were incorporated will be discussed below.

2.2.8.6. The AASP in research

Other research took into account the AASP questionnaire utilised amongst a general population, and a population with psychiatric illness, as will be described below. It is important to note that Brown (2001) emphatically proclaims that Dunn’s (1997) Model of Sensory Processing was not intended to identify

pathology. All individuals have patterns of sensory processing preferences with great degrees of variety amongst adults (Brown, 2001). Certain preferences however could possibly be associated with experiences associated with

psychiatric disability and therefore such investigations were conducted (Brown, 2001). Catana Brown, who is co-developer of the AASP, conducted reliability and validity tests on the AASP, followed by item revision as well as research with people with psychiatric disabilities and those without (Brown & Dunn, 2002).

Brown (1999, as cited in Brown, 2001) conducted a study whereby the AASP was used to examine differences in sensory processing for people with schizophrenia, bipolar disorders and those without mental illness. The study indicated that the schizophrenics presented sensory processing preferences for low registration (neurological threshold) and sensation avoiding (behavioural threshold) (Brown, 2001). The study furthermore indicated that the people with bipolar disorder had sensory processing preferences for sensation avoiding (behavioural threshold) (Brown, 2001). The persons without mental illness depicted sensation seeking (behavioural threshold) characteristics (Brown, 2001). Brown (2001)

acknowledges that a large amount of variability was found amongst all the groups of individuals within this study, with the greatest variability existing amongst the schizophrenics. She therefore encourages replication of this study for more insights and confidence of the findings to be gained (Brown, 2001). Brown (2001) further states that for the persons with psychiatric pathologies, the gained

knowledge of the sensory processing preferences could provide them with practical information that could lead to supportive measures to aid wellness.

Brown (2001) specifically indicates the value the sensory processing knowledge could have for occupational therapists in utilising strategies to address the sensory processing needs. The ideals expressed above by Brown (2001) are similar to the abstract views of the researcher of the present study, whereby the gained SI profile knowledge of first year university students could aid themselves and all university staff involved in providing assistance guided in part by their sensory processing characteristics. Similarly to the cautions expressed by the AASP developers, the instrument is not meant to diagnose pathology and thereby the university students could not be diagnosed in any particular and disadvantageous way.

Based on the above-mentioned research for validity purposes, Dunn (2001) furthermore proposed relationships between sensory processing and temperament and personality characteristics. The quadrant descriptions of the Model of

Sensory Processing were matched with features within the temperament literature.

Quadrant two, which is sensation seeking, was linked to a positive affect of

Quadrant two, which is sensation seeking, was linked to a positive affect of